1. Field of the Invention
The present invention relates to an image pickup apparatus on which an interchangeable lens is removably mounted.
2. Description of the Related Art
In a camera system represented by a digital single-lens reflex camera, a power is supplied from a camera in a state where an interchangeable lens is mounted on the camera, and control information, various kinds of lens data, and the like are sent and received between the camera and the interchangeable lens. For example, when a lens for a moving image as the interchangeable lens is mounted on the camera, it is preferred that a control which emphasizes saving the power is performed since the power supply to the interchangeable lens (power consumption) is increased. A camera exclusively used as an electronic view finder (An exclusive camera for EVF) has one advantage that its size is reduced since a mirror member is not used, but according to this, a flange back (a flange focal length) has to be designed to be short. As a result, it is necessary to perform a control so as to protect an image sensor that does not have a protection member.
Japanese Patent Laid-Open No. 2011-149971 discloses a configuration of issuing a notification command that previously notifies a power cut-off before the power cut-off of the interchangeable lens, and of performing a power cut-off processing between the camera and the lens after information of the lens are stored. Japanese Patent Laid-Open No. 2009-260959 discloses a method of controlling the cut-off of the power after an aperture unit is controlled to be a predetermined light amount at the time of cutting off the power in order to protect an image sensor.
However, as an interchangeable lens removably mounted on the image pickup apparatus, there are lenses such as a lens for taking a still image or a lens for taking a moving image which have usages different from each other. Furthermore, there are an interchangeable lens which has a switch to switch a function such as an AF (autofocus) and an MF (manual focus) or an interchangeable lens which does not have the switch. On the other hand, in the configurations of Japanese Patent Laid-Open No. 2011-149971 and Japanese Patent Laid-Open No. 2009-260959, an appropriate control in accordance with a type of the interchangeable lens, specifically an appropriate aperture control at the time of turning on the power or an appropriate function switching control, cannot be performed.